Analytical balance



ct. 1954 w. c. sEYTER ETAL 2,690,906

ANALYTICAL BALANCE Filed March 28, 1951 6 sheets-sheet 1 jg 129 J3@ 133,i x.; 1 y 1 l1;- Y

l l llllllllu 126 129 123 INVENTORS. 125 r Wuhan: Segler 1130 Wl/afmN'em'er 1,27 Timmers Wndw'ch E2/@MMM l HTTORNE' .S

Oct, 5, 1954 w. c. sz-:YTER ETAL ANALYTICAL BALANCE 6 Sheets-Sheet 2Filed March 28, 1951 274g 7. jf i517 7 Oct, 5, 1954 w. c. SEYTER ET ALANALYTICAL BALANCE 6 Sheets-Sheet 3 Filed March 28, 1951 v INVENTORS'.WEZ-[lam Seyier William [Ye/Ier Thomas Windisch Bm] Oct. 5, 1954 w. c.sEYTER ET AL ANALYTICAL BALANCE jfl Filed March 28, 1951 Oct., 5, 1954w. c. SEYTER ETAL 2,690,906

ANALYTICAL BALANCE Filed March 28, 1951 6 Shee'ts-Sheet 5 www lINVENTORS.

' Wilaya C. .S'eyier Wiliam: Headley Tlwmws Wzdwch 6 Sheets-Sheet 6ANALYTICAL BALANCE WN vmmlN llll|l|||l|||| Ill L? -t fill: IL.

Oct. 5, 1954 Filed March 28, -1951 @r .NN @YR m sw mtMd MQfrm mi# la mau @M d @am [h Wwf H Patented Oct. 5, 1954 UNITED STATES OFFICE ANALYTICAL BALANCE York Application March 28, 1951, Serial No. 217,961

1s claims. l

The present invention relates to weighing scales or balances and aims toprovide certain improvements therein. More particularly it relates tothe type of balance in which a line weighing chain is hung at one endfrom the balance beam and at the other end from a movable carrier,whereby more or less of the chain may be adjusted to bear upon the beam,as may be required for the weighing operation.

The object of the invention is to generally improve the constructionalfeatures of a balance of the type described so that weighing operationscan be more accurately and quickly performed.

The invention comprises the advantages, combinations and arrangements ofparts set forth in the following detailed description and illustrated inthe accompanying drawings, from which the several features of theinvention, together with the advantages obtainable thereby, will bereadily understood by persons skilled in the art.

In the drawings, wherein like reference characters denote correspondingparts throughout the several Views:

Figure 1 is a front elevational view of a balance embodying ourinvention, parts being broken away to better illustrate certainconstructional details.

Fig. 2 is a horizontal sectional View taken along the line 2-2 of Fig. 1and showing the chain carrier bracket assembly.

Fig. 3 is a vertical sectional view taken along the line 3-3 of Fig. 2.

Fig. L1 is a vertical sectional view taken along the line Il-ll of Fig.3.

Fig. 5 is a top plan view with parts thereof broken away to betterillustrate certain details.

Fig. 6 is a top plan View of the magnetic damping assembly.

Fig. '7 is a horizontal sectional view taken along the line 'l--l ofFig. 6, the magnet being shown as withdrawn out of damping position.

Fig. 8 is a vertical sectional view taken along the line ll-l of Fig. 1,the front panel of the balance case being shown in partially openposition.

Fig. 9 is a vertical sectional view taken along the line 9 9 of Fig. 8.

Fig. 1G is a top plan View of the index plate assembly.

Fig. 11 is a vertical sectional view taken along the line H--ll of Fig.10.

Fig. 11a is a horizontal sectional View taken along the line Ila-l la ofFig. 10.

Fig. 12 is an enlarged front elevational view "if the line l-li 0f Fig.14.

Fig. 17 is a top plan View of the bracket assembly for the beam arrest,the pan arrest and the index plate.

Fig. 18 is a Vertical sectional view taken along the line lil-I8 of Fig.17.

Fig. 19 is a vertical sectional view taken along the line lil-I9 of Fig.17.

Fig. 20 is a vertical sectional view taken along the line 2li- 20 ofFig. 17.

Fig. 21 is a top plan view of the rider lifter assembly, with partsthereof broken away.

Fig. 22 is a side elevational view of the rider lifter assembly, withparts thereof broken away.

Fig. 23 is a Vertical sectional View taken along the line 23-23 of Fig.22.

Referring first to Figs. 1, 5 and 8 of the drawings, the referencecharacter 25 denotes a balance case having a base 2li, leveling screws21 and sliding front and rear panels 28 and 29, respectively. Within thecase 25 is a column 30 having at its top an agate bearing 3! upon whicha central knife edge 32 carried by a balance beam 33 is adapted to besupported. The balance beam 33 has suspended from its ends, scale pans3i, and from its midpoint dependingly carries a needle or pointer 35which is adapted to swing in front of a graduated index 36.

The balance case 25 is herein shown as formed of metal and glass, thebase 26 being constituted by an upperbase member 3l and a lower basemember 38, the upper base member supporting a glass base panel 39. Thebalance case and the operational parts thereof are not herein describedin detail as they constitute the subject matter of our co-penclingapplication, Serial No. 217,962, filed March 28, 1951.

The column 3l] is mounted upon a base plate lll which is held onto thetop of the base panel 39 by screws M which extend through plate i2mounted on the upper base member which will be presently described morein detail. A bubble level 40a is mounted in the plate 40. The'column 30is held on the base plate by a hollow bushing 39a having ascrew-threaded nipple 30h extenr ing through an vopening inthe baseplate and The column Lift rod for operating beam arrests In priorbalance constructions, the weight of the lift rod for the beam arrestswas relied upon to cause the rod to fall or descend when dearresting thebalance. Because of the close tolerances in connection with theeccentric pin of the roller shaft for operating the lift rod, the liftrod tongue and the arrest arms of the beam, the tongue always presenteda problem. The ideal, of course, is to have the tongue pull the lift roddown. Because of the difference from balance to balance, it was foundnecessary to have an open slot in the tongue. Adjusting personnelcarefully adjusted the upper surface of the slot to obtain the correctarrestment. The dearrestment, however, depended upon the rod falling byitself, of its own weight.

According to the present invention the rod is positively operated inboth arresting and de-arresting the balance. Within the column 30, whichis hollow, is a lift rod 43 which is guided for vertical movement and tothe lower end of said lift rod there is pivotally connected a link ortongue Lil! and to the upper end of said lift rod are pivotallyconnected the balance beam arrests 65. The lower end of the tongue itlis slotted, as shown at 4S (Fig. 9), and mounted in said slot forlongitudinal adjustment therein is a hollow, screw-threaded stud 'i andlock nut 4S (Figs. 8, 17). Extending through the hollow, screw-threadedstud 41 is a pin i5 eccentrically mounted in the end of a roller shaftd, the opposite end of said shaft extending through the front wall ofthe upper base member and being provided with a control knob 5l. Theroller shaft 5i) is supported in a bearing within a block 52 carried onthe underside of the plate 62, the shaft 5i! being held against axialmovement in said block by a spring-pressed ball 53 engaging in anannular groove 54 in said shaft. For limiting the angular rotarymovement of the roller shaft it is provided with a radially extendingpin 55 which is adapted to contact a pin 5G extending outwardly from theblock 52 parallel to the axis of shaft 58. The relationship of theaxially extending, eccentrically disposed pin 49 and the radial pin 55on the roller shaft 59 is such that, when the shaft 59 is rotated in aclockwise direction, the lift rod i3 will be raised to operate the beamarrests t5 to release the balance beam, and when rotated in acounterclockwise direction to de-arrest the beam and pull down the liftrod. By adjusting the position of the hollow, screw-threaded stud i?within the slot d5 of the link si to provide for the correct lift of thelift rod, a continual contact is provided between the arrest eccentricpin and the lift rod is thereby positively controlled in both its upwardand downward movement, and reliance upon the dropping of the lift rodupon de-arrestment of the balance beam is eliminated.

lift

Pan arrests The pan arrests in prior balance constructions had an arcingmotion which introduced a kick or swinging motion to the balance panswhen the pan arrests were actuated. In addition, the location of the panarrest mechanism on the top surface of the base plate made cleaning thecase extremely dimcult.

According to the present invention as will be readily understood byreferring to Figs. 1, 17 and 19, a pair of pan arrest levers 58 whichare mounted to move in an arc, actuate two adjustable plungers 58 whichhave a vertical movement. rihe plungers 59 each consists of a sleeve 6%slidable Within a bearing 6| mounted in the base panel 39 and heldthereon by a nut 62, the sleeve having adjustably threaded into itsupper end a fiat-headed stud 63 having a felt or similar pad 53a forcontacting the underside of a scale pan 34. The pan arrest levers 58 arepivotally mounted at 64 in proximity to their rear ends to dependingears 65 formed on the plate 42, the rear ends of the pan arrests beingrigidly connected to a weight bar 6B which acts to hold the forward endof the pan arrest levers in elevated position, e. g., in a position tohold the plungers in up or scale pan arresting position. The weight barSt has an adjustable pin 6l which contacts the pan arrest control rod S8which is operable from in front of the balance case by a knurled knob69. At its rear end the control rod fixedly carries a cam 'IU having anend cam surface 'Il against which bears the inner end of the pin 5l',the rod extending through a bearing opening in an ear 'l2 depending fromthe plate t2. To hold the cam against the ear 52 a collar '13 is xedlymounted on the control rod by a set-screw pin T4. By means of theadjustable pin 6l it is possible to properly position the pan arrestlevers in relation to the plungers 59* For limiting the rotation of thecam l0, the pin 'f4 is adapted to engage a stop pin 'I5 extending at aright angle to the ear l2.

Thus with the cam l0, the adjustable pin 6l and the adjustable plungers59 a smooth even pan arrestment is obtained free from the kick whichinvariably accompanies scale pan de-arrestment in conventional balances.

Adjustable pointer index In prior adjustable pointer indexes, thecontrol knob had a direct linkage which caused the rotation of the knobto be translated to the index plate itself. If the knob was accidentallybumped, the index would be moved out of its adjusted position. The priorindexes had the index plate attached to a pendulum which pivoted about apoint at the top of the column. The entire arrangement necessitated acomplicated assembly and costly adjustment.

According to the present invention, the pendulum construction has beeneliminated. Referring now to Figs. 10, 11, 11a, 17, 18 and 20 of thedrawings, the index 36 comprises a plate 'I1 which is mounted on a metalholder 18 which, in turn, is secured by screws 78a to the base plate 4Dwhich supports the column 30. The holder 18 has an arcuate slot "i9, theradius of which coincides with the arc of the pointer 35, and guided insaid slot is a pair of screws 8i] carried by the plate 71 and secured toa connecting spring strip 8l. The holder 'i8 is also formed with arecess S2 the function for which will be presently understood. Henceadjustment of the index plate will cause it to move in the same arc asthe pointer. Actuation of the index is accomplished from below throughan eccentric clutch arrangement now to be described. Secured to theplate TI is one end of an angular connecting rod 83 which is movable inthe recess 82, the intermediate portion of the rod extending through aslot 8d in plate 42 and a recess 85 in block 52, the other end of theconnecting rod being pivotally connected to the shank of a headed screw86 eccentrically mounted and rigidly carried by a sleeved disc lilloosely mounted adjacent one end of a shaft 88, the other end of whichextends through the front of the casing and. carries a knurled knob Sil.As shown, the connecting rod is mounted in spaced relation to the disc8l by a sleeve all. The sleeved disc 8l is held against a depending eart! on the plate 42 by a collar 92 xed on the shaft by a set screw. Thedisc s'i is formed with a diametrical slot Sd into which a cross-pin S5on the shaft is adapted to be positioned when the shaft is pulledoutwardly to provide a clutch and when the clutch is engaged, the disc8l can be rotated by rotating the knob 39. Normally the cross-pin 95 isheld out of engagement with the slot till by a coilspring 96 bearing atone 'end against the inner face of the upper base member 3l and at itsother end against a collar Sl ilxed on the shaft S8. To limit the inwardmovement of the shaft by the spring ii, a collar 98 is fixed on theshaft in predetermined fixed relation to the sleeve 92. To set the zeroon the index 3B which is fixedly secured to the plate ll, the knob 89 ispulled outwardly to engage the clutch and by rotating the knob thepointer can be quickly set at the zero point. When the operator releasesthe knob, the spring Sii disengages the clutch. Hence, it is impossibleto move the setting of the index without intentionally doing so.

Magnet damping assembly In prior balances employing a magnetic dampingmeans, the magnet was generally mounted in fixed relation to the balancebeam, hence, if damping was not desired for any particular weighing,nothing could be done about it.

According to the present invention the magnet is mounted to be quicklyretractable or it may be adjusted to provide for any desired degree ofdamping action. By referring to Figs. 1, 3,6 and 7 of the drawings itwill be seen that we have provided a magnetic damping assembly which isfully retractable and adjustable. In said iigures we have shown thebalance beam 33 as provided at its left end with a thin magneticpermeable plate or vane i083 disposed and extending beyond the beam inthe longitudinal central plane thereof, and adapted for cooperativeaction with said vane there is provided a horseshoe permanent magnetlill. bracket M32 by a screw Ii3 and the bracket is mounted on a squareshank Iilll of a screwthreaded stud it which engages internal threadslil@ in a bushing extension lill carried by a knurled knob Ict. Themagnet damping assembly is movably supported in a side wall of theb-alance case by a flanged bushing ISS, the free end of which isexternally screw-threaded as shown at Iiil, the flange Ill on thebushing being held against the outer face of the side wall of thebalance case by a knurled clamping nut H2 engaging over the threaded endl lil and bearing against the inner face of the side wall of the balancecase. Mounted in the flange iI is a spring-pressed detent I It whichbears upon the bushing extension I which is mounted for slidingengagement within the flanged bushing lila. The bushing extension lillis formed with an annular groove I I Il within which the spring-presseddetent I i3 is adapted to engage when the knob m8 is pushed inwardly tothe limit of its movement. FiXedly mounted in the flanged bushing lill)is a square sleeve I I5, the free ends of which are split as indicatedat I i6 to provide resilient ngers engaging the square shank Hifi. Theshank ltl is pro- The magnet is secured within a U-shaped vided withmarkings III to indicate the position of the magnet with respect to thevane itil. With the present magnetic damping assembly it will beapparent that the magnet may be quickly retracted free of the vane onthe beam if the operator so desires, or adjusted to any desired degreeof damping which can be readily duplicated because of the markings II'I.

Chain carrier In prior balances of the type employing a suspended nneweighing chain, the final adjustments of the chain carrier knife wereextremely difficult. The chain carrier knife edge must be on the sameplane as the knife edges of the balance beam. With prior balanceconstructions this was difficult to obtain. One of the nal adjustmentsto be made in a balance is the line adjustment of the chain to becertain, for the weight of chain involved, that the carrier knife is atthe proper distance from the central knife edge of the beam. This is anextremely delicate adjustment which, in prior balance constructions,usually resulted in a twisting of the carrier knife out of the properplane.

According to the present invention the chain carrier is of aconstruction which insures the exact location of the plane of the chaincarrier knife edge. The carrier is so constructed that adjustments areaccomplished by the mere turning of a screw, in the course of which theplane of the chain carrier knife edge remains unchanged and a finedegree of adjustment can be easily obtained. The construction of thechain carrier will be readily understood by referring to Figs. 1 to 4 ofthe drawings wherein a rightangled carrier bracket H8 has its short armllt secured to a plane face of the balance beam 33 ,Jy a securing screwI2il. The long arm lili of the carrier bracket has a bore therethroughof different diameters |22 and I23. Extending into the end of thebracket adjacent the short arm is a hollow screw-threaded bushing Ilhaving a hexagonal head E25 for facilitating rotation of the bushing. Inspaced relation to the head ld, the bushing is formed with an annularrecess into which extends the end of a set-screw i2? whereby thethreaded` bushing may be rotated within the bracket without anyaccompanying axial movement. Extending through the bore 23 of thebracket arm I2I is the shank H38 of a screw I29, the threads of whichengage the threads within the bushing ift. The shank i223 is heldagainst rotation by being formed with flat side IBI) against whichlightly bears a second set-screw iti. It will thus be seen that as thehexagonal head I25 of the bushing I2@ is rotated, the shank I2il will beaxially moved into or out of the bracket arm itl. Secured to the outerend of the shank i253 is a chain carrier i322 having a knife edge E33which is disposed in a coinmon plane with the plane of the knife edgesof the balance beam. Hence, to make theI proper adjustment of the knifeedge 33 from the central knife edge of the beam it is merely necessaryto rotate the hex head I2 in a proper direction. The knife edge ISS isadapted to support a stirrup I34 having an angular bearing I35 adaptedto seat on the knife edge ISS. The stirrup carries one end of a weighingchain 36, the other end or" which is hung from a movable carrier orrotatable drum presently to be described.

Chain dial and verm'er assembly In United States Patent No. 2,004,745there is disclosed a chain dial and vernier assembly which has been inuse for many years. With the cunstruction shown in said patent,difiiculty has been encountered in connection with the tendency of theweighing chain to loop or sag somewhat from the V-groove at 6 oclockposition on the dial, e. g., if the chain dial was wound up and if ithit the stop pin a trie too hard a loop was formed at 6 oclock positionwhich resulted in insufcient weighing chain being supported on the beam.Also, the location of the dial control knob adjacent the rider controlknob gave rise to a constant source of error due to the dial controlknob being accidentally disturbed when actuating the rider rod.Furthermore, with the construction shown in said patent the Verniercontrol knob extended outwardly from the top of the balance case and,aside from its difiicultly accessible position, the magnitude of theextension depended upon the degree of adjustment which had accumulatedupon repeated adjustments of the Vernier.

According to our present invention the drawbacks recited in thepreceding paragraph are eliminated. By referring to Figs. 1, 5, and l2to 16 of the drawings and the following detailed description, theconstruction and operation of our improved chain dial and Vernierassembly will be readily understood.

Secured to the inner face of the side wall of the balance case is astandard |31 having a rigid arm |36 extending at a right angle thereto,said arm adjacent its free end carrying a xed shaft |39 upon which isrotatably mounted a drum or pulley sheave |46, upon the front face ofwhich is carried a graduated dial |4| which may be calibrated inmilligrams or any other suitable units. The drum |46 is rotatably heldon the shaft |39 between a rotatable bushing |42 and an ornamental coverdisc |43 which is screwthreaded onto the end of the shaft |39. The drumis formed with two annular V-shaped grooves |44 and |45, the groove |44for accommodating the weighing chain |36, an end of which carries asplit spring pin |46 which is held within a radial Slot |41 in the drum,and the groove |45 for accommodating a driving belt, herein shown as achain |48. The driving chain is trained over a pair of pulleys |46, |56,mounted for free rotation on a stub shaft |5| xedly threaded into thearm |38 and over a pulley |52 xed on a shaft |53 mounted for freerotation near the base of the standard |31, one end of the shaftprotruding through the side of the balance case and having xedly mountedthereon an operating wheel |54. To insure proper torque for the drivingchain |48 its ends are joined by a tension spring |55. For limitingrotation of the drum in both clockwise and counterclockwise directionsduring taking up or paying out chain, respectively, the drum is providedon its rear surface with a pair of spaced pins |56, |51 adapted toengage stop abutments at the desired limits of rotation. As statedabove, if the chain drum is rotated to take-up chain and if it hit thestop abutment a trifle too hard, a loop was formed in the chain at 6oclock position of the dial which resulted in insufficient weighingchain being supported on beam. To prevent such looping of the chain wehave provided a novel braking device |58, herein shown as consisting ofan arm |59 pivotally mounted on a screw |60 secured in an upright |6|rigidly carried by the arm |38, the arm |59 having a ange |62 whichcarries an ogee pin |63 having a rubber sleeve |64 enclosing one end ofthe pin. The arm |59 is biased by a leaf-spring |65 to normally hold therubber covered end of the pin out of engagement with the weighing chain,as shown in Fig. 12. The free end of the spring |65 bears upon theupright |6|. A carrier rod |66 has a bearing in the upright |6| and atits outer end screwthreadedly engages in a control knob |61 which has abearing in the standard |31 and extends through the side Wall of thecasing. Accordingly, in rotating the drum |40 in a clockwise direction,the pin |51 will strike the pivoted spring-biased arm |59 just prior toreaching the limiting point in rotation, whereupon said arm is rotatedabout its pivot against the tension of the spring to force the rubbercovered end of the pin into braking engagement with the weighing chain|36 and thus prevent looping of the chain, as shown in Fig. 13. At thelimit of rotation of the drum in a counterclockvvise direction the pin|56 will be brought into engagement with the upright |6| to preventfurther rotation of the drum. The control knob |61 is formed with anannular groove |68 into which extends the end of a set-screw |69threaded into the standard |31 so that the control knob will have rotarybut nonaxial movement. However, rotation of the control knob will impartaxial movement to the carrier rod |66 because of the screw-threadedconnection thereof with the non-axially movable but rotatable controlknob. The carrier rod is bifurcated at its end opposite to that whichengages within the control knob and held in engagement with the base ofthe slot provided by the bifurcation, by a tension spring |16, is theapex end of a substantially triangular shaped Vernier carrier |1|, thebase of which is angularly bent and carries a verneir |12 in a commonplane with the graduated dial |4|. The Vernier carrier at approximatelyits central point is mounted on the bushing |42 for rotation about theshaft |39 xed to the arm |38. For limiting the movement of the carrierrod toward the left so that it will not become disengaged from thecontrol knob |61 there is mounted on said carrier rod a stop sleeve |14adapted to engage the upright |6|. For the purpose of enclosing theoperative mechanism for the chain dial and Vernier assembly andenhancing its appearance, said parts are enclosed within housings |15,|16 suitably secured to the balance case.

From the foregoing detailed description of the chain dial and Vernierassembly it will be apparent that as the operating wheel |54 is turned,the Weighing chain |36 will either be wound upon or payed o the drum |49to Vary the length of the active component of the chain suspended fromthe balance beam. During this action the Vernier |12 will remainstationary and it may then be used to read the dial |4| or may beindependently adjusted to set the zero for the basis of a weighingoperation.

Rider lifter and rider Tod assembly The present invention alsocontemplates an improvement in the rider lifter and rider rod assemblywhereby to facilitate the use and emciency of said parts. Referring toFigs. l, 5, 8, 21, 22 and 23 of the drawings, a rider lifter |13 isslidingly mounted Within a square tubular housing |19 supported at itsends by hanged bearings |80, which are secured to the inner faces of theside Walls of the balance case. The rider lifter |18 comprises aslide-block |8| mounted on a rider rod |82 which protrudes through oneof the bearings 18) and through the side wall or the balance case, theouter end of the rider rod having secured thereto an operating knob |83.The slide-block I8! is formed with a longitudinal recess in its topface, within which recess is disposed a bowed spring 34 which bearsagainst the top inner surface of the housing to resiliently hold theslide-block in any adjusted position to which it has been moved. Theslideblock is also formed with a circular recess at one end within whichis housed a pinion 85 carried at the inner end of the slide rod and witha cross-shaped recess ita in one of its sides within the vertical arm ofwhich recess is movable a rack 86 which is in mesh with the pinion. Tohold the rack in any position to which it has been moved, a bowedT-shaped spring Nibo', is mounted in said recess idea to bear againstboth the rack and the confronting inner surface of the square housing,In alignment with the rack and for accommodating movement thereof in anyposition of the rider rod, the housing ils has formed in its top andbottom walls, registering parallel slots it?, ist. Carried by the rackW6 is a U-shaped rider stirrup iii@ and an indexing disc iiii, thestirrup having parallel, angular bent arms liii, Si formed with aligneddepressions 92 for facilitating the carrying of a dumbbell-shaped rider93. For limiting movement of the rack both upwardly and downwardly,

the rack carries a pair of screws ld, 95, the screw led also serving asva set-screw to hold the stem of the rider stirrup onto the rack. With aconstruction of rider lifter and rider rod assembly as disclosed anddescribed, a smooth, vertical movement is obtained in raising andlowering the rider as the knob i833 is rotated, such action isfacilitated by the indexing disc rearwardly of the stirrup and theconstruction is so sturdy as to eliminate accidental movements of theparts. Moreover, because of the constructional features, the assemblyhas a pleasing appearance.

While we have shown and described a preferred embodiment of ourinvention, it is to be understood that we do not wish to be limited tothe constructional details disclosed, since these may be modi-ned withinthe range of mechanical and engineering skill without departing from thespirit of our invention as defined in the appended claims.

What we claim is:

1, A weighing scale or balance comprising a column, a beam adapted to besupported on the column, beam arrests, a lift rod for arresting andde-arresting the beam and mechanical means for positively operating thelift rod in both arresting and cie-arresting the beam, comprising atongue pivotally connected to the lift rod, adjustable means for varyingthe effective combined length of the lift rod and the tongue and arotatable eccentric mechanically coupled to the tongue.

2. A weighing scale or balance according to claim l, wherein theadjustable means for varying the combined length of the liftrod and thetongue comprises a slot in the tongue, a hollow stud extendingtransversely through said slot and adapted to be held in any adjustableposition longitudinally of said slot and an eccentrically disposed pinon the rotatable eccentric engageable in the hollow stud.

3. A weighing scale or balance having a balance beam adapted to besupported on a central knife edge, a scale pan adapted to be suspendedfrom the beam, a pan arrest comprising a vertically movable plunger andoperative means normally holding the plunger in engagement with theunderside of the scale pan, comprising a pivoted lever, means normallyacting on the lever to hold the plunger in its up position and meansoperable to permit the plunger to move downwardly by its own weight.

4. A Weighing scale or balance according to claim 3, wherein the pivotedlever is a lever of the first class, one end of which is weighted tohold the other end in contact with the plunger to hold the plunger inits up position and cam controlled means operable to permit the plungerto move downwardly by its own weight.

5. A weighing scale or balance according to claim 4, wherein the cam ofthe cam controlled means is adjustable.

ck il weighing scale or balance having a balance beam adapted to besupported on a central knife edge, a pair of scale pans adapted to besuspended from the opposite ends of the beam, and arresting means forthe pans comprising a vertically movable plunger for each scale pan, apivoted lever in engagement with each plunger, means rigidly connectingsaid levers so they will move in unison, means for normally acting onthe levers for holding the plungers in their up position in engagementwith the undersides of the scale pans, said plungers being adapted tomove downwardly by their own weight when the means for holding them intheir up position are withdrawn and a single operable means forcontrolling the levers.

7. A weighing scale or balance having a beam adapted to be supported ona central knife edge, a pointer carried by the beam and a laterallyadjustable index plate movable in an arc coincident with the are inwhich the pointer is movable for cooperation with the pointer, operatingmeans comprising a clutch for moving the index and means normallyholding the clutch disengaged.

8. A weighing scale or balance according to claim 7, wherein the indexplate is mounted above the base plate of the balance and the clutchcontrolled operating means is operable from in front of the balancebelow said base plate.

9. A weighing scale or balance according to claim 7, wherein theoperating means for moving the index plate comprises a lever pivoted atone point to the index and at a remote point being eccentrically mountedon a rotatable member.

lil. A weighing scale or balance according to claim 9, wherein the indexplate is mounted above the base plate of the balance, the clutchcontrolled operating means includes a shaft disposed below the baseplate and operable from in front of the balance below said base plate,the rotatable member to which the lever is eccentrically mountedconstitutes one of the clutch members, the other clutch member beingmounted on the shaft and spring means normally holding the clutchmembers disengaged.

ll. A weighing scale or balance comprising a balance beam having acentral knife edge, a chain carrier fixedly secured to the beam, arotatable drum chain carrier, a weighing chain, suspended at one endfrom the xedly secured chain carrier and at its other end from therotatable drurn carrier, said fixedly secured chain carrier having aknife edge which is parallel to and in a common plane with the centralknife edge of the beam, and means for adjusting the knife edge on thefixedly secured chain carrier toward and away from the central knifeedge of the beam without disturbing the parallel relationship or commonplane of the knife edges, the fixedly secured carrier comprising abracket xed to the balance beam and having an arm parallel to the planeof the balance beam, a non-rotatable but axially movable screw extendingaxially through the arm of the bracket, a rotatable but nonaxiallymovable nut carried by the bracket engaging the screw and the knife edgeelement of said carrier being fixedly mounted on the screw.

12. A Weighing scale or balance comprising a balance case having a baseplate, a balance beam, a Weighing chain suspended at one end from thebeam, a rotatable drum to which the other end of the chain is connectedfor varying the effective Weighing component of the chain, a drivingbelt for said rotatable drum, a pulley Within the balance case inproximity to the base plate of the balance over which pulley saiddriving belt is trained and an operating Wheel exteriorly of the casefor rotating said pulley to rotate said drum.

13. A weighing scale or balance according to claim 12, wherein theoperating Wheel for the driving pulley is located at the side of thebalance case substantially lower than the axis of the drum.

14. A Weighing scale or balance comprising a balance case, a balancebeam, a Weighing chain suspended at one end from the beam, a rotatabledrum to which the other end of the chain is connected for varying theeiective Weighing component of the chain, a driving belt for saidrotatable drum and a trip brake means for engaging the weighing chain asit approaches the limit of its wound-up relation to the drum.

15. A weighing scale or balance according to claim 14, wherein the brakemeans is normally spring-biased out of braking position and cooperatingmeans on the drum and on the brake means for operating the brake whensaid cooperating means are brought into engagement.

16. A Weighing scale or balance comprising a balance case, a balancebeam, a Weighing chain suspended at one end from the beam, a rotatabledrum to which the other end of the chain is connected for varying theeiective weighing component of the chain, a graduated dial rotatable 12with said drum, an adjustable arcuate Vernier for cooperation with theperiphery of the dial, means operable from the exterior of the balancecase for moving the dial and the Vernier independently of each other,and spring means for holding the Vernier in any set position, the meansat the exterior of the case for moving the Vernier comprising a threadedsleeve mounted for rotative but non-axial movement in a wall of thebalance case and a member having axial but non-rotative movementscrew-threadedly engaging the sleeve.

17. A Weighing scale or balance comprising a balance beam adapted tosupport a rider along the top of the beam, a rider rod movable parallelto the beam, a liftercarred by the rider rod for applying and removing arider from the beam, said lifter being movable vertically, said riderrod being rotatable on its axis and having affixed thereto a pinion, andthe lifter having a rack engaging with said pinion.

18. A weighing scale according to claim '17, wherein the pinion and therack are mounted in a slide-block carried by the rider rod, saidslideblock being mounted for resilient engagement with the Walls of axed housing.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 768,829 Thompson Aug. 30, 1904 1,203,686 Becker Nov. 7, 19161,655,118 Voland Jan. 3, 1928 1,900,641 Gattoni Mar. 7, 1933 1,937,223Gattoni Nov. 28, 1933 1,964,349 Gattoni June 26,1934 1,997,636 GattoniApr. 16, 1935 2,081,252 Seederer May 25, 1937 2,102,938 Becker Dec. 2l,1937 2,111,842 Dahlberg Mar. 22, 1938 2,222,658 Gattoni Nov. 26, 19402,230,491 Heusser Feb. 4, '1941 2,295,440 Wassberg Sept. 8, 19422,373,056 Seederer Apr. 3, 1945 2,581,807 Mettler Jan. 8, 1952

